Method for straightening metallic structural members



July 17, 1934; D, K. CRAMPTON METHOD FOR STRAIGHTENING METADLVIC STRUCTURAL MEMBERS Filed May 22, 1935 Patented `uly 17, 1934j FICE METHOD FOR STRAIGHTENING METALLIC STRUCTURAL MEMBERS Donald K. Crampton, Marion, Conn., assigner to The Chase Companies, incorporated, Waterbury, Conn., a corporation Application May 2,2, 1933, Serial No. 672,180

5 Claims.

This invention relates to an improvement in methods for straightening metallic structural members or shapes and relates in p rticular to an improved method for straightening extruded 5 structural members of odd or complex cross-sectional form, such, for instance, as bronze architectural trim in the form of moldings, railings, bars, etc., though not so limited.

The method most commonly used for straight- 10 ening extruded structural members includes a longitudinal stretching operation of sufficient force and scope to eiiect a slight but permanent elongation to thus remove waviness, buckles, kinks, etc., from the mem` er. This operation requires that the members, barsor shapes be rmly gripped at each of their respective o?- posite ends in suitable jaws or chucks. No particular diiiiculty is encountered in so straightening members of `simple cross-sectional form which can be readily gripped over an ample area. However, when the members are of complex cross-sectional form or unduly thin, or both, the problem becomes exceedingly difficult, if not impossible, oi accomplishment by the ordinary method referred to.

it is obvious that it is, in a commercially feasible sense, impossible to provide gripping-jaws or chucks conforming to the transverse forms of myriade of complex members so to secure an adequate and uniformly-distributed grip irectly thereupon. Therefore, when attempts are made to straighten such members oi complex cross-sectional form by the ordinary method, the gripping-jaws or chucks grip only the high spots, Vso to speak, so that the proportion of the cross-section in Contact with the gripping-means is small as compared with the total cross-section. Now, when the member is placed under suricient strain to eirect its straightening, the localised portions thereof, which are actually gripped, are torn out. Numerous devices have been devised to overcome this diiiiculty but without success in a commercial manner.

The main object oi the present invention is to provide a method whereby structural members oi complex cross-sectional form, thinness, or both, may be stretched longitudinally to a sufficient degree tc effectively straighten the same and remove kinks and waviness therefrom.

Other objects and advantages will appear to those skilled in the art from the following, considered in conjunction with the accompanying drawing and the appended claims.

In the accompanying drawing:

Fig. l is a broken perspective view of an extruded structural member or complex cross-sectional form, which may be straightened by means of present invention;

Fig. 2 is a similar view showing the grippingpads in place upon each of the respective opposite ends of the preparatory to stretching;

Fig. 3 is a schematic view in side elevation, showing the member gripped at its opposite padded-ends in the jaws of a pair oi stretchingheads; v f

Fig. Il is a broken View in longitudinal section, taken on the line 4-4 of Fig. 2, but on a` larger scale;

Fig. 5 is a transverse sectional View, taken on the line 5--5 or" Fig. 2, but on a larger scale;

Fig. 6 is a schematic sectional view showing the end of the structural member immersed in a casting-pot for having cast thereon a gripping-pad; and

Fig. .7 is a similar view, but showing the structural member slightly elevated above the bottom of the casting-pot to provide a gripping-pad of a more enveloping nature.

By way oi example, in carrying out the present invention, a relatively long, extruded structural member l0 of irregular or complex crosssectional form and hollow or having a longitudinal opening from end to end, iirst has cast or molded upon its opposite ends, respectively, gripping-pads or coverings ll and 12. These gripping-pads may be composed of a wide variety of materials such, for instance, as tin-lead solder, or other metals or alloys having a lower melting point than material composing the shape lo. if desired, the eripping-pads may be cast or otherwise molded of materials or compounds which may exist in a fluid or plastic state at room temperatures and which solidify by drying or curing such, for instance, as rubber compounds of the type employed in the manufacture of automobile tires.

Such gripping-pads or cove ings, when cast or otherwise molded in place upon the structural member, may assume varied cross-sectional forms, though a rectangular or other polygonal form is preferred, as such form may be ccnveniently gripped. As shown, the extruded structural member l0 includes exterior ribs or projections 13 and channels cr grooves 14 producing a complex cross-sectional form which is overlaid, so to speak, by the gripping-pads 11 and 12, which are of suiicient thickness not sor ico

only to reinforce the respective ends of the member, but to serve to convert the complex cross-sectional form thereof into a simplified form which may be readily gripped by suitable gripping-means. The material from which the said pads l1 and 12 are formed also extends within the hollow interior of the shape as shown, to provide a compression-resisting core 14a.

The member 10, as now equipped at each of its respective opposite ends with a gripping-pad, may be stretched to the point of permanent elongation.y for removing kinks, waves, etc., by any approved stretching-means engaging the said pads. In Fig. 3 is schematically shown a pair of complementary stretching-heads 15 and 16, each of which is provided with a pair of gripping-jaws 17--17.

With the now-padded member in place, as shown in Fig. 3, and its respective grippingpads 1l and 12 solidly gripped by the jaws 17, the movement of the stretching-head 15 in the direction of the arrow A, while the stretching-head 16 is held stationary, Will serve to permanently elongate the member and effectually remove kinks, Waves and other distortions therefrom without breakage thereof, inasmuch as the gripping-pads serve to distribute the pull or draft sufficiently uniformly over the entire cross-section of the member.

Preferably, the gripping-pads 1l and l2 are cast of a tin-lead solder or other metal having a lower melting point than the metal of the member, and which will actually alloy with the metal of the member to be stretched, and thus secures a more effective grip thereon than would be the case were the pads merely held in place by friction. It may be here stated, however, that the pads need not be made of such material as will alloy with the shape, as described, but will serve effectively even though the said pads secure no more than a frictional grip upon the structural members. In any event, the grippingpad is of such composition and character as will serve to distribute the stretching strain over the major portion of the cross-sectional form of the shape.

ln Fig. 6 is schematically shown one end of the member 10 as resting upon the bottom of a casting pot 18 containing, either in a fluid or plastic state, the material from which the gripping-pads are to be formed (preferably molten solder or the like). When cast or molded in the manner shown in G, the gripping-pad will not extend appreciably beyond the end of the shape l0 to which it is applied.

If for any reason it is desired to extend a gripping-pad beyond the end of the member, the said member may be held suspended above the bottom of the casting pot 18, as shown in Fig. 7.

The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are therefore to be considered in all respects as illustrative and not restrictive, and all changes coming Within the meaning and equivalency range of the appended claims are intended to be embraced therein.

, I claim:

1. A method for straightening extruded metallic structural-members having a longitudinal opening therethrough from end to end and comprising: casting or otherwise molding two complementary spaced-apart, solid, block-like gripping-pads on and Within such structural-member, the said pads being or" metallic material alloyed with the material of the structural member; gripping the said gripping-pads; and stretching the structural-member to straighten the same by force applied through the said gripping-pads.

2. A method for straightening extruded thinwalled metallic structural members hollow from end to end and comprising: casting or otherwise molding two complementary spaced-apart gripping-pads on and Within such hollow structuralmember; gripping the said gripping-pads; and stretching the structural-member to straighten the same by force applied through the said gripping-pads.

3. The method of straightening metallic structural members comprising: providing a structural member t0 be straightened, of uniform cross-section throughout its length; molding on the opposite ends of said structural member, two complementary, spaced-apart gripping-pads; removing the molds from said gripping-pads; directly gripping said gripping-pads; and stretching said structural member to straighten without breaking the same, by force applied through said gripping-pads.

4. The method of straightening metallic structural members comprising: providing a structural member to be straightened, of uniform cross-section throughout its length; molding on the opposite ends of said structural member, two complementary, spaced-apart grippingpads; removing the molds from said grippingpads; directly gripping said gripping-pads by opposed gripping-jaws on each gripping-pad; and stretching said structural member to straighten Without breaking the same, by force applied through said gripping-pads.

5. The method of straightening metallic structural members comprising: providing a structural member to be straightened, of uniform cross-section throughout its length; molding on the opposite ends of said structural member, two complementary, spaced-apart gripping-pads of metallic material alloyed with said structural member; removing the molds from said grippingpads; directly gripping said gripping-pads; and stretching said structural member to straighten Without breaking the same, by force applied through said gripping-pads.

DONALD K. CRAMPTON. 

